Johnson Grass

There is some Johnson grass in the pasture I just put my horse in. I heard that it becomes poisonous during drought and after the first winter frost. I have read conflicting accounts on the internet, from it will kill my horse, to horses tend not to eat it, to horses are not as susceptible to the poison as other livestock. Do I need to aggressively get rid of this stuff before fall gets here, or is it not a big deal?

Well the internet isn't co-operating and I can't get the OSU website to open up but:

1. Johnson grass does indeed produce cyanide at certain times of the year. My eye doctor lost a cow when the dumb head jumped the fence and got into a big patch of it. He was able to afford an autopsy just to be sure of that.

2. Lots of folks feed horses Johnson grass hay without issue. Evidently ruminant livestock (like cows) are more susceptible to the cyanide (what ever time of year it's produced) than horses.

My horses won't touch a blade of Johnson grass if there happens to be some mixed in their hay.

I have a huge patch of it in corner up by the road. That whole section is fenced off from the horses because:

A) I don't want my horses by the road.
B) I don't want them eating "live" Johnson Grass just in case, because it would be my luck----------------lollol

Actually, two years ago my neighbor baled that 3 acres where the Johnson grass is and fed it to his horses without any problem. Mine wouldn't touch it with a 20 foot pole. He said my horses aren't hungry enough. I said that's ok, just let me know if any of yours cash in over the winter

I said all of that to say, Johnson Grass is not supposed to be dangerous for a horse but I'm not taking the chance; what everyone else wants to do is up to them

I have heard that is is poisonous when stressed (ie: drought)

If there is enough of the other grasses in the field I would trust the horses will avoid it. If they run out of other grasses and hay isn't being supplemented. They might eat it as last resort.

To be safe when the grass dies down I would throw some bales out for them if possible. I wouldn't want to take the risk of them eating it.

There is a reason that they don't eat it or eat it as last resort. Listen to them. :)

1. No horse ever born knows when the nitrates are too high in a grass for him to eat it without damage. Sorry to burst your bubble!

2. There are two ways that Johnson grass can be toxic. One is when it has been stressed due to drought and gets a rain. The new regrowth has prussic acid. The other situation is when you get a frost and it bites the johnsongrass back and you get quick regrowth. It is ok after about 10 days.

Sorry if that was the inference. That wasn't what I meant when I said my horses won't eat Johnson Grass if it's in the hay.

There's a lot of stuff they won't eat if it's in the hay that they would probably eat if it was "live" in the pasture.

They are picky eaters and I suppose that's my fault for not feeding them crap.

They evidently feel their own field grass is crap once it's been turned into hay because I kept 20 bales for myself the year my neighbor baled and you'd've thought I was forcing them to eat spinich and vinegar. They said "we'd rather starve", so I loaded up those 20 bales and took them to the neighbor for his horses - who didn't have a bit of problem eating it -- weeds, Johnson Grass and all------------------------

My 20 yr. Old OTTB gelding is now dripping and streaming urine constantly. The vet said it looked like neurological damage from Johnson Grass. A urine specimen showed no bacteria, crystals or anything else. It was totally clean. A bladder palpation showed it to be full, but normal. I was astonished because to my knowledge there is absolutely no Johnson grass at the farm where he's been kept for the last 8 years. No other horse there has these problems. Imagine my shock when talking to the farm owner I was told the coastal bermuda hay she's recently been feeding has Johnson grass in it!! And it's not unusual to see it standing in some of the hay fields around here. It really is a noxious weed!! Apparently if it is handled correctly when mature (but not blooming) it is okay hay and some people do feed it. The problem is that some horses are VERY sensitive to it and since mine is older....? None of the other 17 horses at the farm are showing any signs of problems. My vet has said all we can do is watch and wait for it to leave his system AND make sure he never touches any more Johnson Grass. It will either gradually get better, or gradually get worse to the point where he begins to lose control of his hindquarters. At that point I'll put him down because I've been told there is no hope of recovery when it reaches that point.

NEW Johnson grass shoots are full of cyanide and will kill immediately. People do feed the mature stuff and as I say, it does show up accidentally in hay. I gather that if it's mature and handled well, it's ok in small amounts. But to deliberately feed it? Never. Ever. Why take the chance???

Hoping your horse recovers-did you get some different hay in for him?

EXACTLY the same thing as my riding partner's 19 year old OTTB.

Never mind - I didn't realize this is his wife!!!!! Hi Pat.

Johnson Grass is a member of the Sorghum family of grasses. It is a noxious weed to my way of thinging. It can and does cause enough problems when feed to horses or grazed on it that I avoid it like any other known toxic weeds and grasses.

ROFL Hi, Bill!!! (And DB is 20 this year!)